All categories

3 years ago

PLEASE HELP!! In triangle ABC, B= 120 degrees, a=10, c=18, find C

Mathematics

2 answers:

S_A_V [24]3 years ago

7 0

Add all of them then subtract from 180

sveta [45]3 years ago

7 0

Check the picture below. Notice that we can always solve for the cosine and simply use the sides alone to get an angle.

$\bf cos^{-1}\left(\cfrac{10^2+(\sqrt{604})^2-18^2}{2(10)(\sqrt{604})} \right)=\measuredangle C
\\\\\\
cos^{-1}\left(\cfrac{100+604-324}{20\sqrt{604}} \right)=\measuredangle C \\\\\\
cos^{-1}(0.77309903583)\approx \measuredangle C\implies 39.366998916677^o\approx \measuredangle C$

You might be interested in

Need help thank you!

Rudik [331]

Answer:

$216

Step-by-step explanation:

We know that the cost of an outfit for one team member is 10 + 26 + 18 = $54, therefore, the cost of outfits for all 4 team members will be 54 * 4 = $216.

3 0

3 years ago

If the rate of the boat in still water is 27 mph, and the rate of the current of a river is x mph, what is the rate of the boat

BigorU [14]

Answer:

a)27-x

b)27+x

Step-by-step explanation:

when a boat travels in the same direction as the current is downstream-->speeds the boat. If the rate of the boat in still water is 27 mph and the rate of the current of a river is x mph, the rate of the boat when the boat is going downstream is 27+x

when a boat travels against the current is upstream-->slow down. If the rate of the boat in still water is 27 mph and the rate of the current of a river is x mph, the rate of the boat when the boat is going upstream is 27-x

6 0

4 years ago

A group of students calculated their average score at a spelling bee. They realized that if one of them scored 9 more points, th

alukav5142 [94]

Answer: There are 4 students in the group.

Step-by-step explanation:

Let the number of students in the group be n

If one of them scored 9 more points , their average score would be 81 points.

So, our equation (1) will be

$\frac{\sum x+9}{n}=81\\\\\sum x+9=81n$

Similarly,

If one of them scored 3 points less, their average score would be 78 points.

So, our equation (2) will be

$\frac{\sum x-3}{n}=78\\\\\sum x-3=78n$

So, from equation (1) and (2) we get:

$81n-9=\sum x=78n+3\\\\81n-9=78n+3\\\\81n-78n=3+9\\\\3n=12\\\\n=\frac{12}{3}\\\\n=4$

Hence, there are 4 students in the group.

8 0

4 years ago

When Helen jogs, every $20$ minutes she checks the total distance she traversed. One day, the first time she checked, Helen had

german

The difference between speeds, during the first 20 minutes and last 20 minutes, would be 4.3 miles. The key word here is difference which automatically tells us to subtract. In this case you would subtract 6.8 miles, the last 20 minutes, by 2.5 miles, the first 20 minutes. In the end, getting 4.3 miles. Hope this helps! :)

3 0

4 years ago

Solve the following equation. 4w = 14.4

Nina [5.8K]

Answer:

w =3.6

Step-by-step explanation:

4w = 14.4

Divide and make the w by itself

w = 14.4/4

w=3.6

Hope this helped :)

Have a good one!

5 0

4 years ago